Typically, a buckle including a plug and a socket that are detachably connectable to each other is used in various use applications to fasten string members of belts or the like to each other or to fasten a belt or the like to a different article such as a bag body.
Such a buckle should be capable of being easily attached/detached and being reliably kept in a connected state (i.e., the basic functions of the buckle) and, further, is desired to be improved in a guiding function required during a connecting operation and be reduced in overall weight.
A buckle disclosed in Patent Literature 1 is a side release buckle that basically includes a plug and socket, each of which includes a belt attachment. The plug also includes a pair of lock arms provided with engagement portions, which are engaged with the socket at an inside of the socket, so that the plug is connected to the socket.
The socket also includes a body in the form of a hollow cylinder. The body has a plug-opposed end provided with an insertion opening and lateral sides each provided with an operation opening. The lock arms of the plug are inserted into the socket through the insertion opening and the engagement portions are engaged. The lock arms are partially exposed from the operation opening in a connected state so that a user can clasp the exposed parts of the lock arms and move them to disengage the engagement portions.
In particular, the buckle disclosed in Patent Literature 1 includes a guide bar disposed between the pair of lock arms of the plug to stabilize a posture of the plug (i.e., improve the guiding function) during the insertion of the plug into the socket.
The guide bar is to be received in the socket. Alternatively, a socket body of the socket may be provided with a V-shaped or Y-shaped cut formed in conformity with the guide bar so that the guide bar of the plug is fitted in the cut of the socket when the plug is connected to the socket. Such a cut of the socket contributes to preventing an increase in a thickness of the buckle and reducing a weight of the buckle.
A bucket disclosed in Patent Literature 2 includes a guiding arrangement provided to an internal surface of a socket to ensure the guiding function. Further, the buckle has two small-sized guide bars and enlarged cuts in the socket body, thereby further reducing the weight of the buckle.